Preheat the oven to 200C/400F/Gas 6.
Grease the insides of two 7.5cm/3in chefs' rings with butter and lay on a baking sheet lined with non-stick babking paper.
Place the butter, sugar, baking powder, cocoa and flour into a food processor and blend until completely combined.
Add the eight cherries and stir well with a wooden spoon.
Divide the mixture between the two chefs' rings, then transfer to the oven to bake for 10-12 minutes, or until risen and cooked through.
For the sauce, heat the cocoa powder, water and sugar in a pan until the sugar has dissolved and the sauce is glossy and smooth.
To serve, transfer the fondants to dessert plates and remove the rings.
Pour over the chocolate sauce and drizzle a tablespoon of cream over each and garnish with two extra cherries.